1. Beam Position Noise from 500 keV MBO0I06 Dipole Sensor
May 13, 2009

2. Beam Position Noise
The Sensor was installed as part of the Segmented Injector PSS system in early Summer 2006
500 keV Dipole Current Sensor moves beam at frequency other than 60 Hz; about 80 Hz
This is the major source of beam position noise in Injector. 60 Hz line noise sources have been reduced
This noise makes measuring helicity correlated position differences far less accurate; increases the width of position differences. Same for charge asymmetry if there is scrapping in the accelerator
How does it affect the physics program?
30 Hz Helicity Reversal is designed to cancel 60 Hz line noise; Sensor noise will not cancel completely
240 Hz Helicity Reversal for PREx; most sensitive
Qweak at 1 kHz is also sensitive but less than 240 Hz Helicity Reversal
Fine for HAPPEx III and PVDIS. Fix by March 1st , 2010

3. Sensor ON PSS Dipole Magnet Sensor OFF Sensor ON
The PSS dipole is between 0I05 and 0I07.
Sensor ON

4. Sensor ON
PSS Dipole Magnet
Sensor
OFF
Sensor ON

5. 30 Hz PSS Dipole Magnet 250 Hz 1 kHz
The PSS dipole is between 0I05 and 0I07.
1 kHz

6. 30 Hz PSS Dipole Magnet 250 Hz 1 kHz
The PSS dipole is between 0I05 and 0I07.
1 kHz

7. 30 Hz

8. 250 Hz

9. 1 kHz

10. 30 Hz

11. 250 Hz

12. 1 kHz